Farmers are continually trying different spacing between adjacent crop rows to maximize productivity and to accomplish the greatest yield from their acreage. Accordingly, an agricultural implement used to plant seeds along a row must allow the planter row units to be laterally moved relative to each other to accommodate for various row spacings. Similarly, an agricultural implement used to harvest the crop must allow the harvesting row units to be laterally moved relative to each other to accommodate variations in row spacings.
In cotton fields, row spacings between adjacent rows of cotton plants may vary between about 30 and about 40 inches. A typical cotton harvester includes between two and five harvesting row units mounted on a tool bar assembly at a forward end of the harvester. As will be appreciated, harvesting five rows of cotton plants wherein adjacent plant rows are spaced about 40 inches apart or in a skip-row pattern requires a tool bar assembly which is substantially longer than that required for harvesting two, three, or four narrowly spaced rows planted in a solid planting pattern.
Whether it be for cotton harvesters, planters, or other forms of agricultural implements which have row units adapted for lateral adjustment, providing a one-piece tool bar assembly for accommodating all the various accommodations of row spacings and harvesting capacity is impractical to the manufacturer and to the farmer. In view of today's economics, a farmer wanting a tool bar assembly for mounting two or three row units does not want the added cost, weight, and inconvenience of a tool bar assembly which is wider than that required. Moreover, a one-piece tool bar which is lengthwise sized to accommodate five cotton harvester row units arranged in a solid or skip-row pattern relative to each other is too wide for conveniently transporting the agricultural implement from one field to another and can interfere with and thus inadvertently remove crop materials from or cause damage to adjacent plant rows as the implement is driven across a field.
Having separate one-piece tool bar assemblies adaptable for two, three, or four row units results in increased manufacturing cost, area distribution cost, and inhibits a farmer from subsequently increasing the row unit capacity of his agricultural implement unless he buys a wider tool bar than that necessarily required at the time. In addition to problems incurred in their manufacture, wider tool bar assemblies present problems in that they are difficult to ship from one location to another and are inconvenient to handle.
Recent advancements in agricultural equipment, and particularly, in the field of cotton harvesters, allows the harvesting row units to be laterally moved relative to each other along the length of the tool bar. As will be appreciated, lateral movement of the row units relative to each other further elongates the design of the tool bar assembly on which the row units are mounted thereby further complicating the problem of providing a single tool bar assembly for a particular model of agricultural equipment.
Multi-piece tool bar assemblies are not without problems. A major problem with such heretofore known multi-piece tool bar assemblies concerns providing a continuous support surface along which the row units can be laterally moved. Although similar in cross section, a tool bar extension which is to be added to a main tool bar to extend the effective length between opposite ends of the tool bar assembly must have sufficient strength to support one or more row units adapted to be supported thereon and must be aligned with the main tool bar to promote lateral movement of one or more row units thereunto. Additionally, the tool bar extension should be easily and readily matable with the main tool bar so as not to require extensive manual efforts to accomplish addition and removal of the extension from the main tool bar when required.
Thus, there is a need and a desire for a multi-piece tool bar assembly which is suited for use with an agricultural implement and includes one or more support structures which can be readily and releasably fastened to a main support structure to allow the length of the tool bar assembly to be customized to a particular agricultural implement with which it finds utility.